Performance investigation of laminar flow through tube fitted with hyperbolic-cut twisted tape inserts

Abstract

ABSTRACT This paper reports the numerical investigation of heat transfer intensification for hyperbolic-cut twisted tape (HCTT) fitted heat exchanger tube in laminar fluid flow using ANSYS Fluent 19.2. The laminar flow characteristics and thermal performance are examined for varying twisted ratio (3 ≤ TR ≤ 6), cut ratio (0.25 ≤ b/c ≤ 1), width (10 mm ≤ c ≤ 16 mm) over Re = 100–1500. The heat transfer laminar model is validated with standard correlations and available literature. The hyperbolic-cut twisted tape provides a better heat transfer and performance than that of the plain tube. This intensification is due to the hyperbolic-cut geometry, which provides additional vortex fluid flow, resulting in disruption of thermal boundary and better fluid mixing. The optimum performance of 4.82 is achieved for c = 16 mm at Re = 1500. Moreover, the performance of HCTT is further compared with existing works of literature and found HCTT performances better for all values of Re. The correlation is proposed to estimate thermal performance for tube fitted with HCTT in laminar flow. Abbreviations: HCTT: Hyperbolic-cut twisted tape; PEC: Performance evaluation criterion; TR: Twisted ratio; TT: Twisted tape